Nathaniel w



(No Model.)

I N. W. PRATT.

STEAM GENERATOR.

No. 323,882. Patented Aug. 4, 1885.

\NITNESSES INVENTEIH.

TERS. Phowlflhugnwhef, Wash ngton. D. C.

UNITED STATES PATENT ()FFICE.

NATHANIEL W. PRATT, OF BROOKLYN, ASSIGNOR TO THE BABOOGK 8D WIL- OOX COMPANY, OF NEW YORK, N. Y.

STEAM-GENERATOR.

SPECIFICATION forming part of Letters Patent No 323,882, dated August 4, 18 85.

Application filed January 13,1885.

To all whom "it may concern:

Be itknown that I, NATHANIEL W. PRATT, a citizen of the United States, residing at Brooklyn, in the county of Kings and State of New York, have invented a new and useful Improvement in SteaInGeneratOrs, of which the following is a specification, reference being had to the accompanying drawings, forming a part of the same, in which Figures 1, 2, 3, and 4 illustrate various detached and enlarged views of the invention, which will hereinafter be particularly referred to and claimed.

The invention relates to a doorway of special form provided in the setting or brickwork of the boiler, and a door or shutter of special construction and security fitted therein to close and render the sameaccessible to a brush or jet of steam for the purpose of removing ashes, &c., that lodge upon the tubes.

In order to secure this door in the brickwork and form an outwardly-flaring opening, the frame is made in approximately \l-shaped sections, joined together top and bottom by horizontal plates, and built into the brickwork, as shown in Fig. 3, which permits such a degree of horizontal movement of a brush or cleaning pipe as to reach the greatest amount of interior surface and at the same time to expose the least possible amount of door-surface to the heat. The top of the frame r is constructed with avertical flange, r, that projects into a recessed beam, to, which, in connection with the lintel o, prevents the brickwork from springing the frame 1" when it settles. This flange may be set in mortar, as shown in Fig. 3, to prevent an air-leak to the furnace. The door 8 closes tightly against the frame r, and is held shut by means of lockinghandles, (shown at 20', Figs. 3, 4, and 5.) Between the inner wings of the frame 1' a loosely- (No model.)

fitted shutter, t, is hung, to protect the door 8 from the heat and prevent its warping, this shutter and door being so placed in relation to each other that the shutter has to be shut before the outer door 8 will close, as shown in Fig. 3.

It will be observed upon inspection of Fig. 3 that the door-frame r is built into the brickwork, so that the bricks are laid in regular bond, and the flaring opening made Wide enough to permit the door to swing flush uith the inside of the frame, and the shutter in turn to swing back against the door, leaving the opening unobstructed and free to work through.

Having thus fully described my invention, what I claim, and desire to secure by Letters Patent, is-- l. A door frame-work for the purpose specified, consisting of vertical members of V cross-section, joined to horizontal top and base plates, adapted to form a portion of an outwardly-flaring opening, and secured in the brick-work, substantially as described.

2. A door frame-work having a vertical flange cast with the upper cross-piece, combined with a recessed beam, substantially as and for the purpose'sp'ecified.

3. A door frame-work adapted to form a portion of an outwardly-flaring opening, as described, provided with an outer door and an inner protecting door or shutter, both opening outwardly, said doors being fitted to open clear of the passage, and so arranged that the outer door is incapable of closing previous to the closing of the inner door, as described.

NATHANIEL W.- PRATT.

Witnesses:

CHAS. W. FORBES, G. R. WATERBURY. 

